Cosmology—the study of the universe, how it was formed, and what laws govern its evolution—has exploded in the last few decades. But it’s not a new area of human inquiry. In fact, theories about the origin, nature, and structure of the cosmos go back thousands of years.

That’s not to say that ancient cosmologies were anything like our modern scientific theories of the cosmos. Many were more like creation myths or legends. However, in ancient Greece, thinkers like Anaximander, Aristotle, and Ptolemy, to name just a few, developed fairly sophisticated theories about the cosmos based on empirical observations. They looked up to the heavens, saw how the stars moved across the sky, how the sun rose and fell each day, and they developed rational explanations for what they observed.

We ultimately ended up rejecting most of these explanations, but not for a very long time. The cosmological picture inherited from Aristotle and Ptolemy was the dominant one in the west till the seventeenth century. This was the picture that placed an unmoving Earth at the center of a finite universe, with the sun and the other planets revolving around it in concentric circles called “celestial spheres.” Enclosing our universe was the sphere of "fixed stars," also called the "firmament." This marked the divide between the earthly and the heavenly realms. Indeed, the ancients had no sense of solar systems beyond our own, nor of the incredible number of galaxies stretching out into the vastness of space.

Despite inaccuracies in their theories, the Greeks were able to make many accurate astronomical predictions. For example, they could predict eclipses. They also figured out that the Earth was spherical. Considering the tools they had at their disposal, this is very impressive.

But do these ancient theories deserve to be called ‘scientific’? The fact that we have rejected most of them should not persuade us to answer this question in the negative. After all, the history of science is full of wrong ideas. It is only by rejecting bad ideas, and proposing new and improved theories that we make progress in science. The theories we accept now are the best we have, given the cognitive and technological tools currently at our disposal, but they are not immune to revision. This is what separates science from dogma.

Unfortunately, though, that ended up being the fate of ancient cosmology—it became dogma, once the Roman Church got its hands on it. No doubt, that is a big part of the story of why it remained the dominant view of the cosmos for so long. The Aristotelian geocentric model placed humanity at the center of the universe. Everything literally revolved around us, which supported the idea that we were God’s highest creation, that this was all made for us. Besides, the Bible said that the Earth didn't move, and that was the ultimate authority on God's universe. For these reasons, this picture of the cosmos was conferred the status of immune to revision. It was not to be questioned. Anyone who dared to raise doubts about it did so at great risk of punishment, even death. Bruno, an Italian cosmologist who followed Copernicus, was tried for heresy and burned at the stake in 1600 for proposing an alternative picture of the cosmos—an infinite universe lacking any center. A few decades later, Galileo was spared that fate, though he was placed under indefinite house arrest for his heretical Copernican views.

There’s a story we hear about the Scientific Revolution. It ushered in the demarcation of the disciplines. Whereas before there was no clear distinction between science, philosophy, theology, and so on, the Scientific Revolution marks a major shift where science and religion come apart and forever stay apart. No doubt, there is truth to this, but it glosses over some important facts.

Take Newton, the Scientific Revolution’s brightest star, if you’ll pardon the pun. Read his most important writings and you might be surprised to see how the scientific and the theological are completely integrated. For example, he claims that the “Supreme Being” is necessary for the motion of the planets, that without God, nothing in the natural world could account for their movement.

Newton’s talk of a “Supreme Being” is not worlds apart from Aristotle’s talk of an eternal “unmoved mover,” the ultimate cause of all motion in his geocentric universe, though Newton’s language has stronger religious connotations than Aristotle’s. It could be argued that Newton’s appeal to a supreme being was motivated by his religious beliefs in a way that simply is not true for Aristotle, who was, after all, a polytheist. The point is that, while it’s the case that no self-respecting scientist today would ever attribute anything to a “Supreme Being” as part of their cosmology, the separation between science and religion happened incrementally, and not overnight, as the term "revolution" suggests; and the revolution's heroes were sometimes more religious than their ancient predecessors.

The glossy story about the Scientific Revolution also does not give enough credit to ancient cosmologists as true scientists. Of course, their theories later became church dogma, but they are not at fault for that. What is important to note is that their methods—observing natural phenomena and using mathematics and logic to offer reasonable explanations—and the results they achieved—being able to make reliable predictions—go to the very heart of science. Did they get it right? No. But do we have it all right now? That’s highly unlikely. Only time will tell.

Our guest on this week’s show is renowned theoretical physicist Carlo Rovelli, a true intellectual who understands the value philosophy has for science. Check out this interview with him where he talks about his philosophy of science and his views about certainty.

To learn more about A Philosophical Guide to the Cosmos, our eight-episode cosmology series, or to listen to any of the shows, click here.

Comments (14)

MJA

Wednesday, March 9, 2016 -- 4:00 PM

With all do respect, asking a

With all do respect, asking a renowned theoretical physicist about certainty would be the same as asking Mother Goose if the old woman really did live in a shoe. But if you want to ask Mr. Rovelli a theoretical physics question, try one of these: Did the big bang make any sound? Does gravity really have waves or was it a measuring devise that created them? Will smashing atoms lead us to the God particle or would uniting all the atoms in the Universe work better? If the universe is infinite, for surely it is until we know its extent, then wherever we are in the Universe our position would be infinitely centered, are we not? As for the Earth being flat, have you ever been to the Great Salt Lake? The planet where I live isn't round either, there are mountains and valleys and cliffs to sail off of if you are not careful. Who says it's round? And here is a good one: Is nature measurable? Science is measure and physics is nature, and then the science of physics is the measure of nature. So if we can't measure the Universe and the Universe is everything, then we can't measure anything, can we? Hmmmmmm
I have found the certainty of science is no different than the proof of God or religion, ye must have faith in both. Imagine even talking faith on a philosophy blog, but then philosophy has yet to define the truth either, has it?
Certainty, truth and the absolute if I so humbly may, is much more simple than thought, and for those who have yet to see it the truth can surely be taught.
Truth 101 anyone?
=

Gary M Washburn

Thursday, March 10, 2016 -- 4:00 PM

Withal, do respect!

Withal, do respect!
Actually, all the atoms in the universe gathered together would be a black hole (not a whole!) and not a place you would want your atoms to be. A few simple observations of the sun (its declination at noon) made on the same day in different latitudes can easily prove earth a globe, as was done over two thousand years ago. But you could also just jog up a mountain (if you've got the stamina for it) and watch the horizon 'rise' to meet you, and as you can see 'over' it. About black holes. their gravity is not infinite, as is wrongly portrayed in the Star Trek movie (in which the planet Vulcan is destroyed by "red matter"). But its spin is infinite, because there is no dimension to it. Instantly upon the appearance of any dimension its centrieital force would explode it. So, why don't they blow up all over the cosmos? What keeps dimensionality out? Remember, dimensionality in this sense is the best refutation of divine influence. Luckily, these days, if you have a dumb idea, the only one you can censor is yourself! Salt lake? Isn't that where they keep the "Book" of Moron I? Maybe you should try going where there is some dimensionality. What makes science science is the willingness to answer critics without retrenchment (a form of censorship).

Gary M Washburn

Thursday, March 10, 2016 -- 4:00 PM

Hello Mike,

Hello Mike,
I might ridicule your dogmatism (and spelling), but I would not insult you. I have been trying to work our where your steady drumbeat comes from, and the reference to the Great Salt Lake led me to suppose you might be Mormon. The text held sacred by that sect is, of course, the book of Moron I (or, as printed in my copy, MORONI). And, yes, I did read it. But I won't tell you what I think of it lest you think I'm being insulting. If you are not Mormon, I do apologize for the mistake. The instrument used to measure the speed of light, and, with some adaptations, gravity waves, is called an interferometer. It detects even the most minute differences in time and space by overlaying light waves and observing the interference pattern that results. But when you buy a quart of milk you are endorsing the physics of measurement. I really think you would profit from reading Plato's Euthydemus, it would probably amuse you, and should impress, that Plato would let his favorite character be ridiculed so brutally.

MJA

Friday, March 11, 2016 -- 4:00 PM

Science, not just me Gary

Science, not just me Gary realizes the problem of measurement, Heisenberg's uncertainty principle was just the tip of the berg. Science went down the path of QM probability and begs for a solution or certainty again. That certainty can be attained by removing the uncertainty from the equation. Once removed, equal is all that remains. Equality is what science yearns for, the equation Einstein worked and died for. Equal is what mankind fights for. The solution is not only scientific, it unifies everything. Equality unites Science, religion, Justice, absolutely everything.
When all is equal all is One.
Be One,
=

Gary M Washburn

Friday, March 11, 2016 -- 4:00 PM

Global warming deniers use

Global warming deniers use the same argument. Science is honest about its uncertainties, therefore the manifest untruth is what truth is. What you are neglecting is that the uncertainty principle comes with as much certainty as uncertainty. The indeterminacy modifies the determinacy, it does not obviate it at all, as you so persistently suppose. The meaning is the modifier, not the evasion of the modified. If you neglect the modified you haven't a clue about the modifier. You just celebrate it as a license to abandon rigor.
Am I wrong (about the other thing)?

MJA

Saturday, March 12, 2016 -- 4:00 PM

Did Carlo Rovelli, "a true

Did Carlo Rovelli, "a true intellectual" in the show say physics was not interested in certainty?
Could someone who has access to the transcript or a replay of the show please post his response,
Thank you,
=

Gary M Washburn

Gary M Washburn

Sunday, March 13, 2016 -- 5:00 PM

From the Wikipedia page on

From the Wikipedia page on the guy:
For Rovelli, science is a continuous process of exploring novel possible views of the world;[12] this happens via a "learned rebellion," which always builds and relies on previous knowledge but at the same time continuously questions aspects of this received knowledge.[13] The foundation of science, therefore, is not certainty but the very opposite, a radical uncertainty about our own knowledge, or equivalently, an acute awareness of the extent of our ignorance.[13
In other words, as Plato says, the height of wisdom, and the beginning of knowledge, is to know that you do not know. It is a certain context of uncertainty, not a license to promote ignorance. Wikipedia also has some good material on 'interferometry' and 'gravity waves'.

MJA

Gary M Washburn

Monday, March 14, 2016 -- 5:00 PM

What case????? Can you really

What case????? Can you really be so dense as to take that as favoring your position (whatever it is)?
Well, I'll say it once more, knowledge is nothing more than the confidence we have searched for every possible reason to think otherwise. It is never perfect, and it is always open to suggestion. It is most certain it is an open mind. Sniping from deep cover is its inverse. The constant repetition of "=" is extremely incongruous to an attitude of implacable "superiority".
From: https://en.wikipedia.org/wiki/Observable_universe:
It is estimated that the diameter of the observable universe is about 28.5 gigaparsecs (93 billion light-years, 8.8×1026 metres or 5.5×1023 miles),[9] putting the edge of the observable universe at about 46.5 billion light-years away.[10][11]
Jump on the use of the qualifier, if you must, but it doesn't even amount to 'one' if you do. No respect is due.

Harold G. Neuman

Tuesday, March 15, 2016 -- 5:00 PM

All of which illustrates the

All of which illustrates the popular axiom among members of the legal profession: no good deed goes unpunished. Also worthy of note was the now famous quote from Steven Weinberg: With or without religion, good people can behave well and bad people can do evil; but for good people to do evil-that takes religion. How incredibly "spot on", to mimic a current aphoristic phrase heard 'round the country and, perhaps eventually, 'round the world. But, I believe history is, in itself, memetic. Why? because it shows us how various influences and cultural pressures have brought about evolutionary change and fostered advances in all sorts of fields of endeavor. There have been discussions and debates regarding science and philosophy and whether they are preternaturally exclusive, or whether one is better than or preferable to the other. There have also been such discourses concerning the level(s) of superstition connected to religious thought and practice. I submit that science and philosophy need and support each other and that the evolution of cosmology is evidence of such symbiosis. Also, we ought to consider revising the term, scientific revolution. My proposal? scientific evolution.
Your humble servant,
HGN.

Harold G. Neuman

Saturday, December 22, 2018 -- 12:18 PM

Copernicus may not have been

Copernicus may not have been the first heliocentrist, but his method evidently nudged a few ventricles; fired a few neurons. With all the fuss made over this---mostly after his time and during the hey day of the power of the Catholic Church, it was no wonder that Galileo had to adjust his own notions about the facts. Just shows that superstition is powerful and old habits die hard. Fortunately, science has remained ruthless in the face of long odds and the equally great ruthlessness of the churchmen. Rorty's Paradox (page 29 of Consequences of Pragmatism- a lovely trade paperback), is instructive here.

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